1. Field of the Invention
The present invention relates to a silica powder which can be added to a recording material used for an ink jet printer. The present invention also relates to a method for producing the silica powder.
2. Background of the Invention
In recent years, ink jet printers have been widely used in homes and offices because they offer such advantages as low prices, quietness, low running costs, high printing quality and so on. Factors responsible for the widespread use of ink jet printers are that full-color and very fine images can be formed due to the astonishing advance of these printers, that the prices of ink jet printers are lower compared with color laser printers, and so on. Looking to the future, it appears that the demand for ink jet printers will increase more and more as computer penetration increases.
In an ink jet printer, an ink dye in an ink tank is ejected from a nozzle as droplets in accordance with an electrical signal from an computer to record a typeface or image on a recording material. A recording material for an ink jet printer can be formed by coating a transparent ink receiving layer on a base sheet. The base sheet includes a synthetic paper, a polyethylene terephthalate film, and so on. The ink-receiving layer comprises a binder, an inorganic oxide, water and so on as base materials, and can be formed by mixing these components in a slurry. The material for the binder is polyvinyl alcohol, and the inorganic oxide includes silica, alumina and so on. Upon contacting with the ink-receiving layer, the ink dye is absorbed by the binder and the inorganic oxide serves to inhibit the bleeding of the ink.
The properties required for the recording material for an ink jet printer are rapid absorption of the ink, no bleeding of the ink, brightness and sharpness of the resulting image, and so on.
Recently, demand for high definition of images has been increasing. In particular, in the case of printing of photographs, current recording materials for ink jet printers have problems such as bleeding of ink and unsatisfactory gradation in color.
Accordingly, there remains a need for recording materials for ink jet printers which overcome these disadvantages.